As reported in this new Gallup page, headlined "For First Time, Americans Favor Legalizing Marijuana: Support surged 10 percentage points in past year, to 58%," the latest polling data suggests that marijuana reform developments over the last year in a variety of state have had a pretty dramatic impact on public opinion concerning marijuana laws and policies. Here are the basic details via the folks at Gallup:

For marijuana advocates, the last 12 months have been a period of unprecedented success as Washington and Colorado became the first states to legalize recreational use of marijuana. And now for the first time, a clear majority of Americans (58%) say the drug should be legalized. This is in sharp contrast to the time Gallup first asked the question in 1969, when only 12% favored legalization.

Public support for legalization more than doubled in the 1970s, growing to 28%. It then plateaued during the 1980s and 1990s before inching steadily higher since 2000, reaching 50% in 2011. A sizable percentage of Americans (38%) this year admitted to having tried the drug, which may be a contributing factor to greater acceptance.

Success at the ballot box in the past year in Colorado and Washington may have increased Americans' tolerance for marijuana legalization. Support for legalization has jumped 10 percentage points since last November and the legal momentum shows no sign of abating. Last week, California's second-highest elected official, Lt. Gov. Gavin Newsom, said that pot should be legal in the Golden State, and advocates of legalization are poised to introduce a statewide referendum in 2014 to legalize the drug....

Independents' growing support for legalization has mostly driven the jump in Americans' overall support. Sixty-two percent of independents now favor legalization, up 12 points from November 2012. Support for legalization among Democrats and Republicans saw little change. Yet there is a marked divide between Republicans, who still oppose legalizing marijuana, and Democrats and independents.

Americans 65 and older are the only age group that still opposes legalizing marijuana. Still, support among this group has jumped 14 percentage points since 2011. In contrast, 67% of Americans aged 18 to 29 back legalization. Clear majorities of Americans aged 30 to 64 also favor legalization....

Whatever the reasons for Americans' greater acceptance of marijuana, it is likely that this momentum will spur further legalization efforts across the United States. Advocates of legalizing marijuana say taxing and regulating the drug could be financially beneficial to states and municipalities nationwide. But detractors such as law enforcement and substance abuse professionals have cited health risks including an increased heart rate, and respiratory and memory problems.

With Americans' support for legalization quadrupling since 1969, and localities on the East Coast such as Portland, Maine, considering a symbolic referendum to legalize marijuana, it is clear that interest in this drug and these issues will remain elevated in the foreseeable future.

Comments

I suspect changes in public opinion are both causing and being caused by changes in the law. In other words, growing support might have pushed WA and CO to legalize the drug, but those legalization measures may have also boosted support for legalization. For example, people might be less fearful of legalizing marijuana after seeing that the sky hasn’t fallen (yet, anyway!) in WA and CO.
But these poll numbers don’t necessarily mean lawmakers (state or federal) will move to legalize anytime soon. For one thing, the poll only asked about legalization of use. Gallup didn’t ask about the legalization of distribution, and I suspect, based on the strong local backlash against state medical marijuana laws, that the public is much less supportive of marijuana distribution. In addition, the poll doesn’t reveal anything about the strength of preference for legalization, or, relatedly, how important this issue is compared to others, like the economy, marriage laws, health care, etc. In other words, people might be comfortable with legalizing marijuana use, but that doesn’t mean they would actively support legalization or vote for or against a candidate because of her stance on this issue. So I wouldn’t expect such polling numbers to portend any near term action by Congress or state legislatures. Ballot initiatives could be another story. That’s because voters are simply asked to vote for or against an initiative. Initiatives typically concern only one issue, so there are no obvious trade-offs involved. I.e., if you favor marijuana legalization—even slightly—you might vote for a legalization initiative, even if you would never vote for a legislative candidate for that reason alone.